Elevator-stop.



No. 7I6,473. Patented Dec. 23, I902. L. E. PRESCOTT.

ELEVATOR STOP. (Application filed Sept. 3, 1902.! N0 Modei.)

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LEXVIS E. PRESCOTT, OF NEW YORK, N. Y.

ELEVATOR-8T0 P.

.3PEGIFIGAEZION forming part of Letters Patent No. 716,473, dated December 23, 1902.

Application filed September 3, 1902. Serial No. 121,933. (No model.)

To all 11/71/0117, it 122/107 concern:

Be it known that I, LEWIS E. PRESCOTT, a citizen of the United States, residing at the cityof New York, in the borough of Manhattan and State of New York, have invented certain new and useful Improvements in Elevator-Stops, of which the following is a full, clear, and exact description.

This invention relates to elevator -stops adapted to automatically stop the car at the upper and lower limits of its movement and to act independently of any other car-controller.

The object of the invention is to provide a simple and efficient apparatus for this purpose.

In carrying out my invention through the elevator-shaft and over a wheel or other actuating device controlling the hoisting-machine, said cord having two loops, one on each side of the controlling device, said loops being arranged to be lengthened on one side and shortened on the other, and vice versa, by instrumentalities carried by the car and actuated by engagement with devices located at the upper and lower ends of the shaft, such lengthening and shortening of the loops serving to move the controlling device.

The invention will be described in detail with reference to the accompanying drawings, in which- Figure 1 is a somewhat conventional representation of an elevator shaft and car equipped with my improved stop; and Fig. 2 is a side elevation of a portion of the carplatform and the stopping devices mounted thereon,as well as the actuating devices therefor.

The elevator-car is indicated by the platform A, which is guided, as usual, by the side rails B B and shoes I) b. The hoisting-ropes and actuating-machine are not shown; but at G is shown a pulley on a shaft c, which is supposed to connect with the controlling-valve of a hydraulic system or with anelectric switch for an electric motor or any other desired controlling apparatus. By rotating this wheel 0 the proper distance and in the proper direction the actuating-machine is stopped. Under the platform of the car is mounted in suit-able bearings a horizontal shaft e, hav- I train a cord ing a crank-arm fextending upward therefrom and carrying at its free end a grooved shoe 1", mounted to turn slightly for independence of movement. Extending vertically along the shaft is a bar g, having at its upper end an offset or cam portion g turning to the left and at its lower end a similar cam portion g turning toward the right. The shoef embraces this barand traverses it from end to end as the car moves up and down the shaft. At the upper end of the shaft the shoe is thrown to the left by the cam portion g, and at the lower end of the shaft the shoe is thrown to the right by the cam portion g while at all intermediate points the. shoe is held at a mid-position. These movements of the shoe cause the arm f to move to the left and right and correspondingly oscillate the shaft 6. The shaft 6 carries a second arm h, projecting downward and havinga forked end in which are mounted upon a suitable axis two independent sheaves 2' and 2', respectively. At opposite sides of the car and fixed in suitable bearings under the floor are two pairs of sheaves in the same planes with the sheaves it. The pair on one side are letteredj and j and on the other side 70, only one of the latter being seen in the drawings. At the lower end of the shaft and on two opposite sides are arranged two guide-sheaves Z and m, respectively.

0' is a cord, rope, or chain, which is connected at one end to a fixed point, as r, at the upper end of the shaft and leads thence downward and around sheave j, thence around sheave 2', then around sheave j, thus forming a loop 1 2, thence downward and around sheave Z, thence around the controlling-wheel G as many times as may be necessary, thence around guide-sheave m, thence upward and around sheave is, then around sheave t, then around the mate to sheave 75, (not shown,) thus forming a complete loop3 l, and finally to the upper end of the shaft, where the end is fixed at It will thus be seen that two loops are formed in the cord, which pass over the controlling-wheel, one being on each side of said wheel, and it will be obvious that if the loop on one side is lengthened by the sep aration of the pulleys and at the same time the loop on the other side is shortened by the approach of the pulleys that portion of the arrow 5.

cord below the car-platform will have a motion from one side toward the other and the controlling-Wheel will be correspondingly rotated. The oscillations of the shaft e, before described, cause this lengthening and shortening of the loops. When the oscillation is such as to throw the pulleys M to the right, the loop 1 2 is lengthened and the loop 3 4 correspondingly shortened, so that the controlling-wheel is turned in the direction of When sheaves 71 i are thrown to the left, loop 3 4 is lengthened and loop 1 2 shortened, thereby turning the controlling-wheel in the direction of arrow 6. Such rotation of the controlling-wheel serves to stop the machine.

It is obvious that the details of the construction described may be altered without devi ating from the essence of the invention. For instance, the functions of the bar 9 may be performed'by a slot, in which case the shoe f would be substituted by a pin or flat plate running in the slot.

The invention is applicable to all kinds of hoisting apparatus where it is desired to automatically stop the car at the limits of its movement regardless of whether the car car ries an operator or not.

It will be understood that a crank-arm on the shaft 0 may take the place of the wheel (3 and that the cord may then be attached to the end of the crank-arm and pull it either to the right or left.

Having described my invention, I claim In an elevator-stop,the combination of a car, a controlling device therefor, a cord fixed at one end to the upper end of the shaft and leading around pulleys on the car to form a loop, thence passing to the controlling device, thence leading around other pulleys on the car to form a second loop and finally fixed at its other end to the upper end of the shaft, an oscillating shaft carried by the car, an arm attached to said shaft and carrying certain of said pulleys, a second arm attached to said shaft, and a guide in the elevator-shaft with which said second arm engages, said guide having offset portions adapted to throw the arm to the right or left, for the purpose of changing the dimensions of said loops, substantially as described.

In witness whereof I subscribe my signature in presence of two witnesses.

LEWIS E. PRESCOTT. 

